“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?”

“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” was the title of a 1972 speech by Edward Norton Lorenz (1917-2008) before the American Academy for the Advancement of Science. Lorenz originally mentioned a sea gull, but the session convenor, meteorologist Philip Merilees, changed that the title to mention the “butterfly.” The term “butterfly effect” began to be used.
 
Lorenz admitted in his book, The Essence of Chaos (1993), that the idea of a butterfly had been used in a Ray Bradbury short stories and that other analogies had been used much before the 1972 speech.
 
   
Wikipedia: Butterfly effect
The butterfly effect is a phrase that encapsulates the more technical notion of sensitive dependence on initial conditions in chaos theory. Small variations of the initial condition of a dynamical system may produce large variations in the long term behavior of the system. So this is sometimes presented as esoteric behavior, but can be exhibited by very simple systems: for example, a ball placed at the crest of a hill might roll into any of several valleys depending on slight differences in initial position.
 
Theory
The phrase refers to the idea that a butterfly’s wings might create tiny changes in the atmosphere that may ultimately alter the path of a tornado or delay, accelerate or even prevent the occurrence of a tornado in a certain location. The flapping wing represents a small change in the initial condition of the system, which causes a chain of events leading to large-scale alterations of events. Had the butterfly not flapped its wings, the trajectory of the system might have been vastly different. Of course the butterfly cannot literally cause a tornado. The kinetic energy in a tornado is enormously larger than the energy in the turbulence of a butterfly. The kinetic energy of a tornado is ultimately provided by the sun and the butterfly can only influence certain details of weather events in a chaotic manner.
 
Recurrence, the approximate return of a system towards its initial conditions, together with sensitive dependence on initial conditions are the two main ingredients for chaotic motion. They have the practical consequence of making complex systems, such as the weather, difficult to predict past a certain time range (approximately a week in the case of weather).
 
Origin of the concept and the term
The term “butterfly effect” itself is related to the work of Edward Lorenz, based in Chaos Theory and sensitive dependence on initial conditions, first described in the literature by Jacques Hadamard in 1890 and popularized by Pierre Duhem’s 1906 book. The idea that one butterfly could have a far-reaching ripple effect on subsequent events seems first to have appeared in a 1952 short story by Ray Bradbury about time travel (see Popular Media below), although Lorenz made popular the term. In 1961, Lorenz was using a numerical computer model to rerun a weather prediction, when, as a shortcut on a number in the sequence, he entered the decimal .506 instead of entering the full .506127 the computer would hold. The result was a completely different weather scenario. Lorenz published his findings in a 1963 paper for the New York Academy of Sciences noting that “One meteorologist remarked that if the theory were correct, one flap of a seagull’s wings could change the course of weather forever.” Later speeches and papers by Lorenz used the more poetic butterfly. According to Lorenz, upon failing to provide a title for a talk he was to present at the 139th meeting of the American Association for the Advancement of Science in 1972, Philip Merilees concocted Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas as a title.
 
Although a butterfly flapping its wings has remained constant in the expression of this concept, the location of the butterfly, the consequences, and the location of the consequences have varied widely.
 
Wikipedia: Edward Lorenz
Edward Norton Lorenz (May 23, 1917 – April 16, 2008) was an American mathematician and meteorologist, and a pioneer of chaos theory. He discovered the strange attractor notion and coined the term butterfly effect.
   
(Oxford English Dictionary)
butterfly effect n. [for a discussion of the origin of this expression, see E. N. Lorenz Essence of Chaos (1993) 14-15] orig. Meteorol. the phenomenon whereby a very insignificant change in a complex system can significantly alter an anticipated course of events (cf. chaos theory n. (b) at CHAOS n.).
[1972 E. N. LORENZ in R. C. Hilborn Chaos & Nonlinear Dynamics (2000) i. 38 (title) Predictability: does the flap of a butterfly’s wings in Brazil set off a tornado in Texas.]
1979 Amer. Jrnl. Sociol. 85 504 In meteorology, this has been called the ‘*butterfly effect’: ‘even if the atmosphere could be described by a deterministic model in which all parameters were known, the fluttering of a butterfly’s wings could alter the initial conditions and thus..alter the long term prediction.’
1984 J. GLEICK in N.Y. Times Mag. 10 June 40/1 In weather, for example, this translates into what is only half-jokingly known as the Butterfly Effectthe notion that a butterfly flapping its wings today in Peking might affect the weather next month in New York.
 
New Scientist (April 10, 1999)
These days, our expectations are higher: the five-day forecast is now an industry standard. Getting there, however, has taxed even the biggest supercomputers. What prevents accurate forecasts is a simple stumbling block: tiny errors of measurement magnify as time passes. Resolving the matter has spawned meteorology’s greatest contribution to modern mainstream science: chaos theory. A meteorologist at the Massachusetts Institute of Technology, Edward Lorenz, invented chaos theory’s most enduring image when he subtitled an address to the American Association for the Advancement of Science in 1979: “Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?”
 
Google Books
The Essence of Chaos
by Edward N. Lorenz
Seattle, WA: University of Washington Press
1993
Pg. 14:
That distinction at present seems to be ging to the butterfly, which has easily outdistanced any potential competitors since the appearance of James Gleick’s book, whose leading chapter is entitled “The Butterfly Effect.”
 
The expression has a somewhat cloudy history. It appears to have arisen following a paper that I presented at a meeting in Washington in 1972, entitled “Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?” I avoided answering the question, but noted that if a single flap could lead to a tornado that would not otherwise have formed, it could equally well prevent a tornado that would otherwise have formed. I noted also that a single flap would have no more effect on (Pg. 15—ed.) the weather than any flap of any other butterfly’s wings, not to mention the activities of other species, including our own. The paper is reproduced in its original form as Appendiz 1.
 
The thing that has madethe origin of the phrase a bit uncertain is a peculiarity of the first choatic system that I studied in detail. Here an abbreviated graphical representation of a special collection of states known as a “strange attractor” was subsequently found to resemble a butterfly, and soon became known as the butterfly. In Figure 1 we see one butterfly; a representative of a closely related species appears on the inside cover of Gleick’s book. A number of people with whom I have talked have assumed that the butterfly effect was named after this attractor. Perhaps it was.
 
Some correspondents have also called my attention to Ray Bradbury’s intriguing short story “A Sound of Thunder,” written long before the Washington meeting. Here the death of a prehistoric butterfly, and its consequent failure to reproduce, change the outcome of a present-day presidential election.
 
Before the Washington meeting I had sometimes used a sea gull as a symbol for sensitive dependence. The switch to a butterfly was actually made by the session convenor, the meteorologist Philip Merilees, who was unable to check with me when he had to submit the program titles. Phil has recently assured me that he was not familiar with Bradbury’s story. Perhaps the butterfly, with its seeming frailty and lack of power, is a natural choice for a symbol of the small that can produce the great.
 
Other symbols have preceded the sea gull. In George R. Stewart’s novel Storm, a copy of which my sister gave me for Christmas when she first learned that I was to become a meteorology student, a meteorologist recalls his professor’s remark that a man sneezing in China may set people to shoveling snow in New York. Stewart’s professor was simply echoing what some real-world meteorologists had been saying for many years, sometimes facetiously, sometimes seriously.
 
UCLA Daily Bruin
Review: ‘The Butterfly Effect’ flies in the face of convention
By CJ Yu
Thursday, January 22, 2004
“The Butterfly Effect” Directed by Eric Bress and J. Mackye Gruber New Line Cinema
Taking a departure from Ashton Kutcher’s recent slew of romantic comedies, “The Butterfly Effect” is a brilliant sci-fi thriller that catches audiences off-guard, challenging them to think about the extent to which everyday decisions can affect the future of one’s life.
 
In “The Butterfly Effect,” Kutcher portrays a college student, Evan Treborn, who suffers from mysterious memory blackouts. When these blackouts occur, Evan suddenly tunes out for several minutes at a time, and the on-screen action cuts ahead to when he regains consciousness again, typically during a jarring event that is both disorienting and startling to the audience. No one can figure out why or how Evan has inherited this disease.
 
But that of course is not where the story ends. Once Evan’s childhood is established within the film, these blackouts are revealed and become his key to figuring out why these missing moments of time were blocked from his memory, and how he can use this knowledge to relive these moments and change his current circumstances.
 
The title of the film lends itself to a hypothesis of experimenter Edward Lorenz, who was the first to pose the question, “Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” In other words, Lorenz’s hypothesis, based on the mathematical chaos theory, questions whether different outcomes of an event have a strong dependence on slight changes in initial conditions.
 
This definition of the butterfly effect, also displayed before the opening credits, creates the philosophical framework from which this suspenseful tale unfolds.
 
Science Daily
Where To Start To Launch The ‘Butterfly Effect’
ScienceDaily (Feb. 16, 2004) — SEATTLE—“Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?” meteorologist Edward Lorenz once asked in postulating the “butterfly effect,” the idea that the flapping of fragile wings could start a chain reaction in the atmosphere. In today’s world of the Internet the question might be rephrased: Can a single e-mail from Brazil set off a torrent of action in Texas?
 
OCLC WorldCat record
Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas? The JC virus story in multiple sclerosis
by A Achiron; S Miron; Y Shoenfeld
Type:  Article; English
Publication: IMAJ -RAMAT GAN- 7, no. 5, (2005): 283-285
Database: British Library Serials
Other Databases: MEDLINE